Siege: Mighty Avengers
FIGHT TIME--THE MIGHTY AVENGERS versus THE DARK AVENGERS! A rag-tag team of Mighty Avengers are thrust onto the front lines of SIEGE...with no one to lead them! And where's HANK PYM? Trapped in Pym-Space with his greatest enemy, his sinister cybernetic "son," ULTRON!
Collects Mighty Avengers #32-36.